PERFORMANCE OF THE NC-140 CHERRY ROOTSTOCK TRIALS IN NORTH AMERICA
The major rootstocks used in North America for the production of cherry cultivars are seedlings of Prunus avium L. (Mazzard) and Prunus mahaleb L. (Mahaleb). While these rootstocks have been used for more than 250 years, horticultural limitations exist, and new rootstock cultivars are sought which can increase scion productivity, control vigor and widen the range of soil adaptability. A NC-140 trial was established in 1987 to test many new rootstocks in twenty sites in North America with scion cultivars of ‘Montmorency’ sour cherry or one of two sweet cherries, ‘Hedelfingen’ or ‘Bing’ (eastern and western North America, respectively). The rootstocks under test included those from Belgium (the GM series); those from Giessen, Germany (the GI series); a series of Mazzard x Mahaleb (MxM) hybrids originally selected in Oregon; Prunus mahaleb clones (the St. Lucie or SL series) selected at Bordeaux, France; Colt, a P.avium x P. pseudocerasus hybrid from East Malling, England; and the current standard rootstocks, Mazzard or Mahaleb seedlings. Because of the complexity of multiple scion evaluation at various sites and that of non-uniform rootstock treatments, this report is presented to highlight the performance of scion cultivars on various rootstocks within each location and followed by a summary on general performance in the overall trial. Geographical location and sweet cherry scion cultivar appeared to play a major role in rootstock performance. In western locations, 'Bing' on GI 148/1 was as vigorous as Mazzard, and in the east, 'Hedelfingen' was 38, 51 and 114% the size of trees on Mazzard at Michigan, New York and Ontario, respectively. Scions on Gisela stocks were generally very precocious. Early in the trials, sweet cherry was impressively productive on GI 148/1 and GI 195/1. However, as the trees in most plots reached the sixth growing season, shoot length reduced to only a few inches per year and branches appeared to become spur bound. The precocious Gisela rootstocks also had a tendency to change the canopy morphology of cherry cultivars. In general, trees on these rootstocks had a tendency to be more spreading and wide open in growth habit. Generally, 'Montmorency' was consistently most productive on Mahaleb seedling and Mahaleb clonal SL 275 and MxM 39. Canopies of 'Montmorency' on Gisela stocks had a tendency to produce a large amount of blind wood, caused by the precocious influence on buds of one-year-old wood. 'Hedelfingen' was most yield efficient on GI 154/7 rootstock. The largest fruit was produced on GI 154/7 and MxM 2; the smallest on GM 9. 'Hedelfingen' was most vigorous on Colt, MxM 2 and Mazzard. 'Bing' was most yield efficient on GI 148/1 and GI 148/2; Colt was the least yield efficient. 'Bing' fruit size was largely influenced by crop load relative to canopy area, MxM 2 consistently had large fruit and GM 9 consistently had small fruit. 'Bing' was most vigorous on Colt, the MxM series, Mazzard, Mahaleb, and GI 148/1. Sweet and sour cherry orchardists are encouraged by the NC-140 authors to experiment, on a limited scale, with those new rootstocks reported in this first test that exhibit horticultural merits for particular site, market, and/or scion requirements.
Perry, R., Lang, G., Andersen, R., Anderson, L., Azarenko, A., Facteau, T., Ferree, D., Gaus, A., Kappel, F., Morrison, F., Rom, C., Roper, T., Southwick, S., Tehrani, G. and Walsh, C. (1997). PERFORMANCE OF THE NC-140 CHERRY ROOTSTOCK TRIALS IN NORTH AMERICA. Acta Hortic. 451, 225-230